Syrian Private University Medical Terminolo… · controlling, receiving, and interpreting all...
Transcript of Syrian Private University Medical Terminolo… · controlling, receiving, and interpreting all...
Syrian Private UniversityMedical Faculty
Medical Terminology
M.A.Kubtan , MD – FRCS
Lecture 12
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The Nervous System
Spinal
Cord
Brain
Nerves
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ObjectivesAfter studying this chapter, you will be able
to:
•Name the parts of the nervous system and discuss
the function of each part.
•Define the combining forms used in building words
that relate to the nervous system.
•Identify the meaning of related abbreviations.
•Name the common diagnoses, laboratory tests,
and clinical procedures used in testing and treating
disorders of the nervous system
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Objectives Part 2 •Define the major pathological conditions of the
nervous system.
•Define surgical terms related to the nervous
system.
•Recognize common pharmacological agents used
in treating disorders of the nervous system
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Structure and Function
Cell body
Dendrites
Axon
Myelin Sheath
Neurilemma
Terminal end fibers
Neurons (nerve cells)
are the basic
elements of the
nervous system.
All bodily activities, voluntary and involuntary, are
controlled by the nervous system.
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Cell BodyCell Body
•The main processing center of the cell
Dendrites
•Thin branching extensions of the cell body
that conduct nerve impulses toward the cell
body.
Axon
•A single branch (in most neurons) which conducts
nerve impulses away from the cell body.
•Myelin sheath and neurilemma are coverings.
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Impulse TransmissionImpulse Transmission
Terminal end fibers are located at the ends of the axon and
they transmit impulses leaving the neuron across a synapse
to the next neuron.
Neuron
A
Neuron
B
neurotransmitter
synapse
All neurons have two basic properties
excitability
conductivity
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Three Types of NeuronsThree Types of Neurons
Conveys information from the
CNS to muscles and glands
Carry information from
sensory receptors to the CNS
•Efferent (motor)
•Afferent (sensory)
•Interneurons
Carry and process sensory
information
Other Cells (Neuroglia)
Support, protect,
connect and remove
debris from the
nervous system
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Types of Neuroglial CellsTypes of Neuroglial Cells
Astrocytes
•Star-shaped
cells that
maintain the
nutrient and
chemical levels
in neurons
Oligodendroglia
•Produce myelin
and help in
supporting the
neurons
Microgli
a
•Phagocytes,
they remove
debris
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Central Nervous SystemCentral Nervous System
•Consists of the brain and spinal cord
•The control center of the body responsible for
controlling, receiving, and interpreting all stimuli
•Sends nerve impulses to instruct muscles and
glands to take or respond to certain actions
•Both voluntary and involuntary movements are
controlled
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BrainBrain
•Weighs about 3
pounds in adults
•75% water
•Contains over
100 billion
neurons
•Controls bodily
functions and
interactions with
the outside
world
Divisions of the Brain
•Brainstem •Diencephalon•Cerebellum •Cerebrum
Midbrain
Pons
Medulla
Oblongata
Diencephalon
Cerebrum
Skull
Meninges
Convolutions (gyri)
Fissures
Corpus
callosum
Cerebellum
Spinal cord
Brainstem
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BrainstemBrainstem
Made up of the midbrain; pons and the medulla oblongata
Midbrain
•Involved with visual reflexes
Pons
•Located between the midbrain and the medulla oblongata
•Controls certain respiratory functions
Medulla Oblongata
•Contains centers that regulate heart and lung functioning,
swallowing, coughing, vomiting and sneezing
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CerebellumCerebellum
Area that coordinates
musculoskeletal
movement to maintain
posture, balance, and
muscle tone
balance
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CerebrumCerebrum
•Located above the cerebellum
•Contains two hemispheres with
an outer portion called the
cerebral cortex
•The two hemispheres are
connected by a bridge of nerve
fibers that relay information
between the two hemispheres
called the corpus callosum
•The left and right lobes are
each divided into four lobes or
parts:•parietal lobe
•frontal lobe
•temporal lobe
•occipital lobe
Temporal
Frontal
Parietal
Occipital
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DiencephalonDiencephalon
The deep portion of the brain containing:
-thalamus
-hypothalamus
-epithalamus
-ventral thalamus
Functions
•Serves as relay center for sensations
•Integrates with the ANS in the control of:
Heart rate Blood pressure Temperature control
Water and electrolyte balance
Digestive functionsBehavioral responses
Glandular activities
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Spinal CordThe brain sits inside a protective bony structure
called the cranium and is surrounded by a
watery fluid, cerebrospinal fluid (CSF), that
cradles and cushions the brain. Ventricles or
cavities in the brain also contain this CSF.
Spinal Cord
•Extends from the medulla oblongata of the brain to the area
around the first lumbar vertebra in the lower back
•Nerves from the peripheral nervous system extend out from
the spinal cord
•Protected by: -vertebral column
-cerebrospinal fluid
-meninges
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MeningesMeninges are three layers of membranes that
cover the brain and spinal cord.
Layers of the meninges
dura mater
•Outer tough fibrous
membrane
arachnoid mater
•Middle weblike membrane
containing CSF
pia mater
•Innermost layer containing
several blood vessels
Skull
Pia mater
Dura
mater
Subarachnoid
space
Arachnoid
space
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Peripheral Nervous SystemPeripheral Nervous System
Consists of 12 pairs of cranial nerves and 31 pairs
of spinal nerves
Cranial Nerves
I olfactory
Function
Sense of smell
II opticSense of vision
III oculomotor Eye movements
IV trochlear Aids muscles that move the eyes
V trigeminal Eyes, tear glands,scalp,
forehead,teeth, gums, lips,
and mouth muscles
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Cranial NerveCranial Nerve Function
VI abducens Muscle conditioning
VII facial Taste, facial expressions, tear and
salivary glands
VIII vestibulocochlearHearing and equilibrium
IX glossopharyngeal Pharynx, tonsils tongue and
carotid arteries; stimulates
salivary glands
X vagus Speech, swallowing, heart muscle,
smooth muscle and certain glands
XI accessory Muscles of the soft palate, pharynx,
larynx and neck
XII hypoglossal Tongue movement
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Somatic Nervous SystemSomatic Nervous System
•Responsible for receiving and processing sensory
input from the skin, muscles, tendons, joints, eyes,
tongue, nose and ears as well as excite the
voluntary contraction of skeletal muscles.
Autonomic Nervous System
•Carries impulses from the central nervous system
to glands, various smooth muscles, cardiac muscle
and various membranes.
•Stimulates organs, glands, and senses.
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Sympathetic Division of ANSSympathetic Division of ANS
•Operates when the body is
under stress to activate
responses necessary to
react to dangerous
situations.
HELP!!!
Parasympathetic Division of ANS
•Operates to keep the body in
homeostasis or balance under
normal conditions.
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Combining Forms and
Abbreviations (cerebell)Combining Form Meaning
cerebell (o)
cerebr (o)
crani (o)
encephal (o)
gangli (o)
gli (o)
mening (o)
cerebellum
cerebru
m
cranium
brain
ganglion
neuroglia
meninges
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Combining Forms &
Abbreviations (myel)Combining Form Meaning
myel (o)
neur (o)
spin (o)
thalam (o)
vag (o)
ventricul (o)
bone marrow, spinal cord
nerve
spine
thalamus
vagus nerve
ventricle
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Combining Forms &
Abbreviations (Ach)Abbreviation Meaning
Ach
ALS
BBB
CNS
CP
CSF
acetylcholine
amyotrophic lateral
sclerosis
blood-brain barrier
central nervous system
cerebral palsy
cerebrospinal fluid
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Combining Forms &
Abbreviations (CAT)Abbreviation Meaning
CAT scan
CVA
CVD
EEG
ICP
LP
computerized (axial)
tomography
cerebrovascular accident
cerebrovascular disease
electroencephalogram
intracranial pressure
lumbar puncture
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Combining Forms &
Abbreviations (MRA)Abbreviation Meaning
MRA
MRI
MS
SAH
TIA
magnetic resonance
imaging
multiple sclerosis
subarachnoid hemorrhage
transient ischemic attack
magnetic resonance
angiography
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Electrodiagnostic ProceduresElectrodiagnostic Procedures
Electroencephalogram (EEG)
•A record of the brain’s electrical impulses.
•Capable of detecting abnormalities that signal certain
neurological conditions.
Nerve Conduction Velocity
•Procedure where peripheral nerves are shocked while timing
the conduction.
Polysomnography (PSG)
•A recording of electrical and movement patterns during
sleep to diagnose sleep disorders.
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Imaging ProceduresImaging Procedures
Magnetic resonance imaging (MRI)
•The use of magnetic fields and radio waves to visualize
structures.
Magnetic resonance angiography (MRA)
•The imaging of blood vessels to detect various abnormalities.
Positron emission tomography (PET)
•Procedure that produces brain images using radioactive
isotopes and tomography.
Computerized (axial) tomography (CAT) scans
•Tomography used to show cross-sectional radiographic
images.
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X-Ray ProceduresX-Ray Procedures
Myelogram
•An x-ray of the spinal cord
after a contrast medium is
injected.
Cerebral angiogram
•X-rays of the brain’s blood vessels
after a contrast medium is injected.
Encephalography
•Radiographic study of the
ventricles of the brain.
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ReflexesReflexes are involuntary muscular
contractions in response to a
stimulus.
Babinski’s reflex is a reflex on the plantar
surface of the foot.
Patellar (Knee) reflexes are usually tested
for responsiveness.
Cerebrospinal fluid can also be withdrawn and
tested for the presence of various substances
that signal certain diseases.
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Pathological TermsConditions Caused By Trauma
Concussion
•Injury to the brain from an impact with an object.
Contusion
•A bruising of the surface of the brain without penetration
into the brain.
Subdural hematoma
•A tumor-like collection of blood often caused by trauma
in which there is bleeding in the dura mater and the
arachnoid or at the base of the dura.
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Congenital DisordersCongenital Disorders
Spina Bifida
•Defect of the spinal column.
•Meningocele is the protrusion of the
spinal meninges above the surface of
the skin.
•Meningomyelocele is the protrusion
of the meninges and spinal cord.
Tay-Sachs
•Genetic disease characterized by
an enzyme deficiency that causes
deterioration in the CNS’s cells
Hydrocephalus
•Overproduction of the CSF in the brain
back of infant with
meningomyeloocele
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Degenerative DiseasesDegenerative Conditions
Alzheimer’s Disease
•Progressive degeneration of neurons in the brain,
eventually leading to death.
Amyotrophic Lateral Sclerosis
•Also known as Lou Gehrig’s disease
•Degenerative disease of the motor neurons leading to loss
of muscular control and death.
Huntington’s Chorea
•Hereditary disease with uncontrollable, jerking
movements and progressive loss of neural control.
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Degenerative Diseases Part 2 Degenerative Conditions cont’d
Multiple Sclerosis (MS)
•Destruction of the myelin sheath leading to muscle
weakness, unsteady gait, paresthesia, extreme fatigue,
and some paralysis.
Myasthenia Gravis
•Condition of muscle weakness due to an overproduction
of antibodies that block neurotransmitters from sending
proper nerve impulses to skeletal muscles.
Parkinson’s Disease
•Degeneration of nerves in the brain which causes tremors,
weakness of muscles, and difficulty walking.
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Neurological Conditions
Neurological
Conditions
Cerebral PalsyBell’s Palsy
AtaxiaEpilepsy
Tourette Syndrome
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Infectious ConditionsInfectious Conditions
Shingles
•A viral disease caused
by the herpes zoster
virus.
Meningitis
•Caused by bacteria and viruses
•Bacterial causes can be fatal
Inflammatory Conditions
•Neuritis
•Encephalitis
•Duritis
•Myelitis
•Radiculitis
•Sciatica
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Abnormal GrowthAbnormal Growth
Gliomas
•Tumors that arise from neuroglia
Meningiomas
•Tumors that arise from the meninges
Ganglion
•Any group of nerve cells bunched together to form a cyst
Vascular Conditions
•Cerebrovascular accident (CVA)
•Transient ischemic attacks (TIA)
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Surgical TermsNeurosurgeons are the physicians that
perform surgery on the brain and spinal
cord.
Surgical Procedures
Lobectomy
•Removal of a portion of the brain
Craniectomy
•Removal of part of the skull
Neuroplasty
•Surgical repair of a nerve
Neurectomy
•Surgical removal of a nerve
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Pharmacological TermsAnalgesics
•Relieve pain
Anticonvulsants
•Treat epilepsy
Narcotics
•Relieve pain by
inducing a stuporous or
euphoric state
Sedatives & Hypnotics
•Relax the nerves and
sometimes induces sleep
Anesthetics
•Numb the body locally (one
section), or general (entire body)
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Apply Your KnowledgeInjury to which of the following parts of the brain
will most likely lead to balance and coordination
problems?
A. medulla oblongata
B. cerebellum
C. cerebrum
Answer : B. cerebellum
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Apply Your Knowledge Part 2Anthony is on his way home from a friend’s
house when several wild dogs begin to chase
him. As he runs, his heart rate and
respiration all increase.
Which of the following nervous system
controls were responsible for preparing his
body to run due to his fear?
A. central nervous system
B. parasympathetic nervous system
C. sympathetic nervous system
Answer: C. sympathetic nervous system
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Apply Your Knowledge Part 3Match each description with the correct medication.
Hypnoticanticonvulsant
Analgesic
Prevents
convulsions
Induces
sleep
Relieves
pain
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Apply Your Knowledge Part 4Identify the labeled lobes
of the brain
frontal
temporal
occipital
parietal
A.
B.
C.
D.